Impeller pump



April 18, 1961 E. EGGER IMPELLER PUMP Filed Sept. 16, 1957 IN V EN TOR.

Fl-r'roausg nite States HVTPELLER PUMP Emile Egger, Cressier-pres-Neuchatel, Switzerland Filed Sept. 16, 1957, Ser. No. 684,328

4 Claims. (Cl. 259-9) The present invention relates to impeller pumps and more particularly to an impeller pump for simultaneously transporting and homogenizing an inhomogeneous liquid.

The impeller pumps according to the prior art are capable of transporting liquid, but cannot produce a mixing of the liquid by which an inhomogeneous liquid is homogenized while passing through the pump.

It is one object of the present invention to overcome this disadvantage of the known impeller pump constructions, and to provide an impeller pump capable of simultaneously mixing and transporting an inhomogeneous liquid.

it is another object of the present invention to provide an impeller whose vanes are shaped in a particular manner to produce a thorough mixing and homogenizing of a liquid transported thereby.

It is another object of the present invention to provide impeller vanes which are shaped contrary to the hydraulic principles applied in conventional pumps, and for the purpose of tearing the liquid stream entering the pump so that the liquid separates from the trailing faces of the impeller vanes to create zones of reduced pressure behind the trailing faces of the impeller vanes.

It is also an object of the present invention to provide for the impeller, a tubular stator Which is curved so that the pumped liquid enters the stator in horizontal direction, and leaves the stator in vertical direction.

A further object of the present invention is to provide an impeller pump capable of transporting and mixing a liquid entering through a pump inlet which communicates with the atmosphere.

With these objects in view, the present invention mainly consists in a pump for homogenizing and transporting an inhomogeneous liquid, the pump comprising, in combination, a tubular stator member, and an impeller located in the tubular stator member adjacent'the inlet. thereof, the impeller including a hub portion and a plurality of impeller vanes which are shaped for not only transporting a liquid, but also for forcing the liquid to separate from at least a surface portion of the trailing faces of the impeller vanes, while the liquid passes along the leading faces of the vanes. Thereby, zones of reduced pressure are created behind the trailing faces of the impeller vanes which results in a thorough mixing of the liquid until the same is rendered homogeneous.

The front edges of the impeller vanes, that is the edges facing the inlet of the pump, have a radius of curvature, a thickness, and general shapewhich effects a tearing of the liquid stream entering the pump, so that the liquid separates from the trailing faces of the impeller vanes at least in the region of the front edges. The turbulence created thereby elfects the homogenizing of the liquid. which however passes in a laminar flow along the leading faces of the impeller vanes. The zones of reduced pressure behind the trailing faces of the impeller vanes, also permit the pumping of liquid having a high content of gases which pass from the liquid into the zones of reduced pressure. The vacuum in the zones of reduced pressure Patented Apr. 18, 1961 also serves to accelerate the liquid, and permits it to connect the pump inlet to the atmosphere so that the pumped liquid can be supplied to the pump inan open stream.

According to the preferred embodiment of the present invention, the tubular stator of the pump is curved and has a horizontal inlet portion and a vertical outlet portion. The impeller according to the present invention is arranged in the inlet portion of the curved tubular stator, and has a horizontal axis. Thereby, the liquid pumped by the impeller is raised to a higher level.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

Fig. 1 is an axial sectional view of an impeller pump according to the present invention; and

Fig. 2 is a transverse section of an impeller vane according to the present invention taken on line 2--2 in Fig. 1.

Referring now to the drawings, and more particularly to Fig. 1, a tubular stator 1 has a circular inlet 2 and a circular outlet 3 having the same diameter as inlet 2. The inlet 2 is located in a vertical plane, and the outlet 3 is located in a horizontal plane, and the tubular stator is constituted by an elbow pipe. An opening 4 is provided in the tubular stator member 1, a drive shaft 5 passing through the opening 4. Bearing means 6 are secured to the stator 1 and include bearings 7 supporting shaft 5 for rotation about a horizontal axis which coincides with the axis of the circular inlet 2, and with the axis of the annular surface 1a adjacent the inlet 2.

The impeller 10 is secured to the end of shaft 5, and includes an impeller hub 11 which is hollow and streamlined.

A plurality of impeller vanes 12 is secured to the hub 11, each impeller vane having a root portion 13 projecting into a hole 14 in the impeller hub and being secured to the hub 11 by suitable means 15 located inside the hollow impeller hub 11.

It is evident that rotation ofthe drive shaft 5 will effect transportation of a liquid entering the inlet 2 through the tubular stator 1 until the liquid leaves through the outlet 3.

In accordance with the present invention it is not only desirable to transport the liquid to a higher level, but also to render the pump capable of pumping inhomogeneous liquids while simultaneously mixing such liquids until the same are completely homogeneous.

Known impeller pumps are designed in accordance with hydraulic principles so that all the liquid entering the pump inlet moves along the leading faces and trailing faces of the impeller vanes. The impeller vanes according to the present invention are designed and constructed contrary to the accepted hydraulic principles, since in accordance with the present invention it is not desired that the liquid flow in a continuous flow along leading and trailing faces of the impeller rings.

The particular shape of the vanes by which a separation of the pumped liquid is obtained at least part of the trailing faces of the impeller vanes, depends on many factors, for example the viscosity of the liquid, the ratio between the solid content and the liquid part of the respective liquid, the speed of rotation of the impeller, and it is difiicult to give a theory of the construction of the impeller vanes according to the present invention. However, it will be understood that the impeller vanes according to the present invention have to be shaped in order to produce separation of the respec-,

chosen to obtain the desired result.

' arrows 26.

tive liquid from the trailing faces of the impeller vanes when the impeller rotates at a selected speed.

It has been found afterconsiderable experimentation by testing practical embodiments of the presentinvention,

from the shape or the cross sectionof conventional impeller vanes. Hub 10 is rotated by shaft insuch a direction of rotation that they convex face 12b leads'and the concave face 12a trails. The thickness 20 in the region of the front edge of the impeller vanes is about three times the thickness 21- in the region of the rearedge of the impeller vanes. The front edge portion 22 is strongly curved toward the trailing face 12:: of the impeller vane 12, whereas the rear edge portion 23 has a lesser curvature. 'Ihe'radius of curvature of the front edge 22' is greater than the corresponding radius in conventional impellers, and the angle of the front edge portion 22 with respectto a plane perpendicular to the axis of rotation of theimpeller, has to be carefully When the impeller vane according to the present invention is properly designed for the particular viscosity The impeller vane 12 While the invention has been illustrated and described as embodied in an impeller pumphaving impeller vanes creating a zone of reducedpressure behind the trailing faces thereof, and having as stator an elbow pipe, it is not intended to. be limited to the details shown, since various modifications and structural changes may be made Without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the 'gist of the present-invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint 'of' priorart, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended Within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A pump for homogenizing and transporting an inhomogeneous liquid and comprising, in combination, a curved tubular stator member having an inlet portion terminating in a circular inlet and an outlet portion transverse to said inlet portion and terminating in a circular and consistency .of the liquid to be pumped and mixed, 7

the liquid entering the pump parallel to the 1 axis of I rotation of the impeller, will be torn behind the "front edges 22' of the impeller vanes 12, and will separate from'the trailing face 12a at least adjacent the front edge 221but preferably along the entire trailing face 12a, as illustrated by the shadedarea 25. At the. same time, the liquid flows along the convex leading A t faces 12b of the impellerv vanes, as indicated by the In the region of the concave trailing faces 12a, the liquid will-flow in direction of the arrows" 27 so that directly adjacent the trailing faces 12a, a vacuum zone of reduced pressure iscreatedi The liquid passing in direction of the arrows 27 creates a zonejof turbulence behind the rear edges of the vanes resulting-in thorough 'mixing and homogenizing of the liquid.

Impeller 'vane's of this type. have a twisted "shape, and 'in'order to obtain the' best possible results, the outerliquid, whereas. in conventional impeller. pumps, "all the a most portions of the 'vanes, which 'move at; the highest outlet; an impeller having an axis of rotation coaxial with said circular inlet, said impeller being located in said tubular statormember adjacent said inlet and including a hub portion and a plurality of impeller vanes projecting from said hub portion,.said impeller'vane's being shaped fortransporting to said outletfan inhomogeneous liquid entering said inlet, each of said-impeller vanes having a front edge portion facing said inlet anda rear edge portion, and having in {a transverse" section a convex leading face and "a concave trailing face connecting said front edge portion and 'rear edge portion, saidconvex faces of said vanes facing toward said inlet, a first portion ofsaid trail ing face located adjacent said front edge portion being more concave than a second portion of said trailing face adjacent said rear edgeportion, said front edge portions having a selected radius of curvature and a selected thickness whereby during rotation ofsaid impeller at a'selected speed the liquid is forced to separate at least from said first portion while passing along the leading faces of said impeller vanes whereby zones of reduced pressure are created behind said first portions of said trailing faces and the liquid is rendered homogeneous; and means'for rotating said impeller at said selected-speed with said convex {faces leading and said concave faces trailing. 7

a 2. A pump for homogenizing and transporting an inhomogeneous liquid and comprising, in combination, a tubular stator member having aninlet and an outlet; an

"impeller located in, said tubular stator member and being driving power isusedjfor,transporting theliquid. On

the other hand, due to the formatio n ofa zone of reduced pressure behind theftra'iling f'aces'of the'impeller vanes,

the. speed. of entry of the liquid is increased since the vacuum zones produce a suction effect.

If thecross section of a conventional impeller vane i is compared with the impeller vane according tothe present invention, 'it will be found that the conventional vane isthinner, less curved, and-hasa front edge, por- .tion defining a smallerfanglewith" a- 'p laneperpendicular.

to the axis. of 'rotationl aThe sha e of a'vane according to the present invention fcor'respondsto agcertain-e'xtent .to the: shape of a wing of a'slow'flying airplane, whereas the conventional vane, has. a shape corresponding to' the shape of a wing of a fast flying plane in which no'separatiori ofthe air 'is desired In "a slow flying plane, the

creationof a vacuuru; zone underneath the wing 'is de-' siredfor producing a greater It be understood that each I 'scribedabove, 'or two or more together, may also find a of the element's 'd-l [useful application in other types of impeller. pumps T fl r mi s ty e dep i d a -.31;

rotatableiinone directionabout an axis ofrotation, said impeller including a' hub' portion, and a plurality of impeller vanes projecting from said hub; portion, said impeller vanesbeing'; shaped, for transporting to said 'outletan inhomogeneous liquid entering said inlet, each of impeller vanes havinga front edge portion confront ing said inlet and a rear edge portion, and having in' a transverse section a-convex leading face and a concave trarhngface connecting said front edgelportion and rear 1 edge portion, saidconvexfaces of said-vanes facing te ward said inlet; a n d meansconnected to said hub portion,

for rotating said impeller in said one direction of'rotation with said convex face's 10f said vanes leading and said concave faces trailing whereby during'rotationof said impeller the liquid is forced toiseparate from saidconcave trailing faces while passing along said convex leading faces'ofsaid vanes whereby .zones "of reduced pressure are created, behindsaid trailing faces,:and turbulence is created behindsa'id trailing edges and the liquid is rendered homogeneous. V V 7' p "3. A pump for homogenizing and transporting an inhomogeneous liquid andcomprising, in combination, a tubular stator niember having an inlet and an outlet, and

a cylindrical surface adjacent said inlet; an impeller rotatable in one direction about an axis of rotation coinciding with the axis of said cylindrical surface and located in said tubular stator member, said impeller including a hub portion and a plurality of impeller vanes projecting from said hub portion toward said cylindrical surface, said impeller vanes being shaped for transporting to said outlet an inhomogeneous liquid entering said inlet, each of said impeller vanes having a front edge portion confronting said inlet and a rear edge portion, and having in a transverse section a convex leading face and a concave trailing face connecting said front edge portion and said rear edge portion, said convex faces of said vanes facing toward said inlet, a first portion of said trailing face located in the region of said front edge portion being more concave than a second portion of said trailing face located in the region of said rear edge portion; and means connected to said hub portion for rotating said impeller at a selected speed in said one direction with said convex faces leading and said concave faces of said vanes trailing so that the liquid is forced to separate from said trailing faces while passing along the leading faces of said impeller vanes whereby zones of reduced pressure are created at least behind said first portions of said trailing faces and turbulence is created behind said rear edge portions whereby the liquid is rendered homogeneous.

4. A pump for homogenizing and transporting an inhomogeneous liquid, and comprising, in combination a tubular stator having an inlet and an outlet and an annular surface between said inlet and outlet; and an impeller rotatable in one direction and having an axis of rotation coaxial with said annular surface and located in said tubular stator member adjacent said inlet, said impeller ineluding a hub portion, and a plurality of impeller vanes projecting from said hub portion toward said annular surface, said impeller vanes being shaped for transporting to said outlet an inhomogeneous liquid entering through said inlet, each of said impe ler vanes having a front edge portion confronting said inlet and a rear edge portion, and having in a transverse section a convex leading face and a concave trailing face connecting said front edge portion and said rear edge portion, said convex faces of said vanes facing toward said inlet, said front edge portions having a selected radius of curvature and a selected thickness, the thickness of each impeller vane in the region of said front edge portion being substantially three times the thickness of said rear edge portion; and means connected to said hub portion for rotating said impeller in said one direction at a selected speed with said convex faces leading and said concave faces of said vanes trailing so that the liquid is forced to separate at least from said trailing faces While passing along the leading faces of said impeller vanes whereby zones of reduced pressure are created behind said trailing faces and turbulence is created behind said trailing edges whereby the liquid is rendered homogeneous.

References Cited in the file of this patent UNITED STATES PATENTS 613,775 Parson Nov. 8, 1898 2,382,535 Bauer Aug. 14, 1945 2,682,925 Wosika July 6, 1954 FOREIGN PATENTS 567,978 Great Britain Mar. 12, 1945 

